1. Technical Field
The present invention relates generally to optical switching, and more particularly to methods and apparatus for free-space optical switching using planar lightwave circuits (PLCs).
2. Description of the Related Art
PLCs have proven to be a convenient platform for fabricating components of lightwave communication systems. PLCs offer the advantages of precise manufacturing, a small form factor, and simple packaging and thermal stabilization.
Arrayed waveguide gratings (AWGs) have become the ubiquitous multiplexer/demultiplexer technology for optical wavelength division multiplexing. PLCs that include AWGs illustrate the numerous advantages of PLC technology. The functionality of an AWG on a PLC, however, is currently limited to solutions that can be implemented only in a planar structure.
Components for lightwave communication systems based on free-space optics enable the use of micro electromechanical systems (MEMS) that are compatible with free-space beam propagation. Optical switching modules based on MEMS technology provide a scalable technology that can interconnect thousands of ports, due to the full use of the three-dimensional volume associated with free-space optics. Free-space based optical components, however, have to address the packaging, alignment, stability, and thermal drift issues of bulk optics. These issues become more severe as the number of components increases.
Accordingly, it would be beneficial to design an optical component which is not limited to planar structures and which takes advantage of PLC technology and the scalability of free-space optics while addressing the issues of packaging, alignment, stability and thermal drift.